Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 11 4 2016 12 25 507 514 Adel SPOTIN Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Sanaz TAGHIZADEH EGHTEDAR Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Abbas SHAHBAZI Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Asghar SALEHPOUR Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Seddigheh SARAFRAZ Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran AND East Azerbaijan Province Health Center, Tabriz Health Center, Tabriz, Iran Seyyed Ali SHARIATZADEH Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Mahmoud MAHAMI-OSKOUEI Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran AND Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 2016 12 25 2016 12 25 Background: The aim of this study was to identify the Trichomonas vaginalis strains/haplotypes based on identifying their probable variations in asymptomatic patients referred to Tabriz health centers, northwestern Iran. Methods: Sampling was taken from 50-suspected women to T. vaginalis in northwestern Iran. The obtained samples were smeared and cultured. Fifty DNA samples were extracted, amplified and identified by nested polymerase chain reaction and PCR-RFLP of actin gene using two endonuclease enzymes: MseI and RsaI. To reconfirm, the amplicons of actin gene were directly sequenced in order to identify the strains/haplotypes. Results: PCR-RFLP patterns, sequencing and phylogenetic analyses revealed definitely the presence of the G (n=22; 73.4%) and E (n=8; 26.6%) strains. Multiple alignments findings of genotype G showed five haplotypes and two amino acid substitutions in codons 192 and 211 although, no remarkable unique haplotype was found in genotype E. Conclusion: The accurate identification of T. vaginalis strains based on discrimination of their unknown haplotypes particularly those which are impacted on protein translation should be considered in parasite status, drug resistance, mixed infection with HIV and monitoring of asymptomatic trichomoniasis in the region. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1350 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/1350/628